In most textile spinning frames and similar machines which repetitively form strand packages upon rotatable spindle assemblies, a limited number of coils of strand material are wound about a spool-like lower portion or member of each spindle assembly before each completed strand package is doffed from the blade-like upper portion or member of the assembly. This is accomplished, in machines having a vertically movable ring rail and a fixed spindle rail, by lowering of the ring rail to a "doff" position below its stroke of normal package-building movement, and simultaneous driving of the spindle assembly through the desired limited number of revolutions. While subsequently ensuing doffing of the completed package separates its strand connection with the coils, the latter maintain connection between the spindle assembly and the strand source pending and during commencement of the formation of a new package. Formation of the new package therefore may be and is commenced automatically when the rail and spindle assemblies are caused to resume their normal operating movements.
After formation of a new package has been commenced, the coils upon the spool of the spindle assembly are no longer necessary or desirable. U.S. Pat. No. 4,208,865, the disclosure of which is incorporated herein by reference, discusses some of the problems presented by such coils and a preferred technique for their elimination. In accordance with such technique or method, the strand connection formed during "start-up" between each set of coils and the "new" strand package is separated after commencement and prior to completion of the formation of such package. This should result in clearance of the coils, relatively promptly and in a substantially intact condition, from the spool of the rotating spindle assembly. A number of effects or influences tend to produce this desired result. Always present ones are the centrifugal and "windage" forces imposed upon the coils by the spindle assembly's rapid rotative movement. The coils may also be periodically subjected to blasts of air from a traveling pneumatic cleaner such as is customarily associated with a textile spinning frame or similar machine. Additionally, some type of mechanical cleaner device may be and usually is present in spaced adjacent relationship to the periphery of the spool of the rotating spindle assembly. The rotative movement of strand material displaced outwardly from the spool periphery, as by centrifugal and/or windage forces, and engaging a mechanical cleaner device is impeded by such engagement. This causes the connected strand material, including any disposed more closely adjacent the spool's periphery, to be subjected to forces which "worry" the same and tend to effect disengagement thereof from the spool.
It has been found, however, that the desired prompt and complete clearance of coil forming strand material from the spindle assembly spool does not reliably ensue in certain situations. One such situation is presented when, during formation of the coils upon the spool of the spindle assembly, the coil-forming strand material overlaps or crosses over itself. In a overlap situation, the overlapping strand material is always closer than the overlapped material to the material's end which is "downstream" in relation to the direction of rotation of the spindle assembly and which is urged by rotation-induced windage toward, rather than away from, the spool. The overlapping strand material therefore forces the overlapped material against the underlying body of the spool, and thus prevents or at least delays clearance of the coil-forming strand material from the spool. Delayed clearance of the coil forming strand material from the spool usually results in at least partial disintegration of the material into undesirable "fly". It additionally may result in the material moving downwardly upon the spool to a location from which its clearance is more difficult, if not impossible.
A second situation wherein prompt clearance of the coil forming strand from the spool does not reliably ensue is when adjacent ones of the coils laterally attach to each other with an attaching force of significant magnitude. This situation is most likely to arise when the strand is comprised at least in part from, and has outwardly projecting tendrils of, synthetic fibers having high strength and tenacity and a relatively long (e.g., 1.5 inches) staple length. As such material passes onto the spindle assembly spool during the coil forming operation, the twist-induced rotative movement which it then undergoes about its axis enhances the tendency of laterally engaging coils of the material to become firmly attached to each other by the tendrils projecting therefrom. Coils thus firmly attached to each other are less likely to be promptly cleared from the spool than are coils which are not so attached.
The amount of strand material wound upon the spool during each coil forming operation also is quite relevant to the relative ease or difficulty of the material's subsequent clearance. Maintainance during machine start-up of the connection between the strand source and a conventional spindle assembly spool, which customarily has knurling upon its peripheral surface, may require the presence of seven or more coils upon the spool when its knurling is worn and/or when the material is of a particularly "slippery" type. Subsequent clearance of the resulting two to three feet of coil forming strand material from the spool is much more time consuming and difficult than the clearance of a smaller amount of strand material. Upon clearance thereof from the spindle assembly spool, assuming that such does eventually transpire, the longer length of strand material is also much more likely to be cast onto and become entangled about an adjacent cleaner device or even the spool or some other part of an adjacent spindle assembly. This undesirable result is less likely to occur when the strand material is of shorter length.